Implement attachment having a hydraulically controlled locking function

ABSTRACT

An implement attachment for a working machine. The implement attachment comprises lock plungers having a hydraulic actuator. The lock plungers are arranged for locking co-operation with an implement. Hydraulic medium supply means is arranged for supply of hydraulic medium to the actuator. The hydraulic supply means is provided with a measuring device arranged to measure the volume of hydraulic medium that is supplied to the actuator. A working machine provided with the implement attachment and use of the implement attachment are included.

FIELD OF THE INVENTION

The present application relates to an implement attachment for a workingmachine, which implement attachment comprises a lock plunger meansprovided with a hydraulic actuator and arranged for locking co-operationwith an implement, and hydraulic medium supply means for the supply ofhydraulic medium to the actuator.

The invention also concerns a working machine provided with an implementattachment according to the invention.

In a second aspect of the invention, it relates to a use of the inventedimplement attachment.

BACKGROUND OF THE INVENTION

During the last decades, the use of implement attachment systems forquick replacements of buckets and implements in connection with workingmachines such as wheel-loaders, material handlers and other machinetypes has become a matter of course on most markets in Europe.Simultaneously, the development has gone quickly from simple mechanicalsolutions, wherein the driver leaves the driver's cab and by a simplelever movement locks or unlocks the locking mechanism of the attachment,to hydraulic solutions, wherein the driver by a simple pressing of abutton in the driver's cab regulates a lock cylinder that actuates thelocking mechanism of the attachment. In the most recent years, alsofully automatic implement attachment systems have started to enter themarket. Here, the coupling and uncoupling of mechanical and hydraulicbuckets and implements are carried out fully automatically directly fromthe driver's cab. Also hydraulic hoses and electric cables are connectedautomatically.

Accordingly, in EP 602 165, such a system and an implement attachmentand working implements included in the same are disclosed. The systemdisclosed in EP 602 165 entails considerable advantages by the fact thatconnection, clamping and hydraulic and electric interconnection of theimplement attachment and the working implement can be carried outwithout the operator needing to leave his seat in the working machine.

Most implement attachment systems are based on the principle that theimplement attachment has a “capturing side” and a lock side. Mostimplement brackets have the same apart from symmetric bracketattachments that in mechanical design can be coupled and locked from twodirections. The capturing side of the attachment picks up the implementand turns it into position and then locks the implement by a lockingmechanism in the form of a lock dowel or lock lip, which enters into alock state of the implement bracket. The locking mechanism eitherextends in the coupling direction of the attachment or 90° transverse tothis direction. Implement bracket is the part of the working implementthat is connected to the implement attachment.

In the system disclosed by EP 602 165, the locking system consists of abar element, a so-called bracket pin on each side of the implementbracket and of two U-shaped and two L-shaped, respectively, grips of theimplement attachment. When coupling together, the U-shaped grips serveas prong-shaped capturing means, the same being brought to straddle thebracket pin on the corresponding side of the implement bracket, whichbracket pin constitutes grip means. Next, the implement attachment andthe working implement are turned in relation to each other around thebracket pin straddled by the U-shaped grips into a position where theother bracket pin abuts to the L-grip. In the same position, lockplungers are pushed out into the L-shaped grips in order to, togetherwith the L-grip, surround the other bracket pin. Thereby, the workingimplement is clamped to the implement attachment. At the same time asthe locking movement is executed, the hydraulic coupling units of theimplement attachment are moved for coupling together with thecorresponding hydraulic coupling units of the working implement.

In the coupling-together disclosed in EP 602 165 and other similarsystems, problems may arise as regards guaranteeing a correctcoupling-together.

Furthermore, by WO 2004/072387, a system for improved safety whencoupling together an implement with an implement attachment ispreviously known.

The system comprises sensor means and detection means arranged for thetransfer of information from the sensor means to the detection means.The sensor means has at least one sensor unit arranged on one of theimplement attachment and the working implement. The detection means hasat least one detection unit arranged on the other one of these. By thissystem, an improved safety is achieved, but requires the presence ofrelatively sensitive components in a harsh and dirty environment.

A specific problem with this kind of coupling-together of an implementwith the implement attachment is the possibility of determining if thelock plunger or plungers becomes/become correctly positioned in relationto the other bracket pin, i.e., the element of the implement thatco-operates with the lock plunger for the locking.

If the lock plunger, when it is to be activated for locking, isincorrectly directed, there is a risk of the locking not beingaccomplished. In certain mispositions, this brings the lock plunger tostrike against the bracket pin. However, normally this is a relativelysmall problem since it is easy for the driver of the working machine toobserve this. In other mispositions, the lock plunger may end up on thewrong side of the bracket pin. This is more difficult to detect for thedriver since the lock plunger has not encountered any obstacle in theactivation stroke and as the view normally is obscured to be able to seethis with the eyes. If the driver then, in belief that the implement iscorrectly attached, lifts the same, there is a risk of accidents whenthe implement come loose.

The object of the present invention is to overcome this problem and in asimple way eliminate or at least reduce the risk of this kind ofincorrect coupling-together.

DESCRIPTION OF THE INVENTION

In accordance with the invention, the object set forth is attained bythe fact that an implement attachment of the kind mentioned by way ofintroduction has the special feature that the hydraulic supply means isprovided with a measuring device arranged to measure the volume ofhydraulic medium that is supplied to the actuator.

Since the stroke length of the plunger means normally is directlyproportional to the supplied volume of hydraulic medium to the actuatorthereof, measuring of the volume gives an indication of how long thelock plunger means has been displaced. The volume that represents thestroke length that corresponds to correct clamping can easily bedetermined.

A volume that is smaller than this indicates that the lock plunger meanshas been prevented from reaching the lock position, e.g., by its outerend having struck against the bracket pin with which the lock plungermeans co-operates during locking. This state is admittedly relativelyeasy to determine ocularly from the position of the driver and istherefore in many cases not so important to detect via the volumemeasurement.

A volume that is greater than the one corresponding to the correctstroke length indicates that the lock plunger means has been displacedtoo far. This may occur if the lock plunger means during the lockingmovement is misaligned so that the lock plunger means ends up on thewrong side of the bracket pin of the implement by which lockingco-operation is provided. When the lock plunger means ends up on thewrong side, there is normally nothing that stops the movement of theplunger means before the actuator thereof has reached its end position,or otherwise the movement of the plunger means is stopped by an obstaclethat stops the movement later than what is the case in the correctlocking position. The measurement of the supplied volume of hydraulicmedium thereby indicates a volume that is greater than the onecorresponding to the correct locking position and tells therefore thatthis state is present. This is the most serious state since it isdifficult to observe ocularly from the driver's cab.

The invented implement attachment that accordingly clearly indicatesthis kind of misconnection makes it possible to avoid continuedoperation with the incorrect connection. The connection process can beinterrupted and remade. Thereby, a considerable risk of an accident isavoided. The invented technique to obtain this indication isextraordinarily simple and reliable, and is in addition relativelyinsensitive to intrusion of dirt and the like that is common in theenvironment where the invention normally is used.

According to a preferred embodiment of the invention, the hydraulicmedium supply means comprises a supply line, and the measuring device isarranged to measure the flow through the supply line.

The arrangement of the measuring device in this way, so that it measuresthe flow through the supply line, is a simple and reliable method todetermine the volume of hydraulic medium that is supplied to theactuator.

According to an additional preferred embodiment, the measuring devicecomprises a restriction in the supply line and a pressure sensor on eachside of the restriction.

By the pressure sensors, data about the pressure drop across therestriction is obtained. Based on the pressure drop, by applyingBernoulli's equation, it is in a simple way possible to calculate theflow through the restriction and the volume of hydraulic fluid suppliedtherethrough.

Calculation of the flow versus the pressure drop becomes more exact thesmaller the restriction is in relation to the dimension of the supplyline. However, the risk of clogging sets a lower limit of the dimensionsof the restriction. Suitably, the restriction has a flow passage areacorresponding to a diameter of 0.5-1.5 mm and a length in the intervalof 0.5-2 mm. In this range, a so-called hydraulic restriction isproduced, whereby the flow calculation becomes very accurate.

According to an additional preferred embodiment, the measuring devicecomprises a calculation unit arranged to receive signals from eachpressure sensor and provided with a calculation program comprising analgorithm defining the volume flow velocity through the supply lineversus pressure levels detected by the pressure sensors and anintegration algorithm integrating the volume flow velocity for thecalculation of the supplied quantity of hydraulic medium.

By the fact that the measuring device is pre-programmed to adequatelytransform detected pressure levels into information about the flowlevel, it is guaranteed that indicated flow volume is correct. Thereby,the risk of mistakes due to an incorrect handling of the pressure levelinformation is eliminated.

According to an additional preferred embodiment, the measuring device issignally connected with an indicator.

Thereby, the recorded information can be presented to the driver of themachine to quickly take actions, if required. Suitably, the indicator islocated in a place easy to access for the driver, e.g., in the workingmachine's driver cab.

According to an additional preferred embodiment, the indicator isarranged to trigger a warning signal when exceeding a predeterminedmeasured volume.

By this embodiment, a complete chain from measuring to adequate actionis achieved. The driver does not need to bother about interpreting themeasured values but is presented a result in the form of OK or not OK.The warning signal may be given on a display, as a sound-signal, or as acombination of the same.

According to an additional preferred embodiment, the lock plunger meanscomprises that each lock plunger is provided with an abutment surfacearranged for application against a body of the implement when theimplement is clamped to the implement attachment. The body that theabutment surface of the lock plunger abuts against is suitably a bracketpin at the capture side. The abutment establishes a distinct stop forthe movement of the lock plunger and creates thereby a pronouncedreference of the position of the lock plunger upon correct locking,which represents a reference volume to which the supplied volume duringa locking movement can be related. In this way, it is easy to determineif the lock plunger has been displaced too far or not.

According to an additional preferred embodiment, the implementattachment comprises hydraulic coupling means for the connection to theimplement and valve means for selective connection of the supply line toeither the actuator of the lock plunger means or to the hydrauliccoupling means.

Such a valve means makes it possible to use the same hydraulic mediumsupply for the locking as well as the operation of the implement, whichmeans a simplification and a saving in costs. Thanks to the reversiblevalve means, the hydraulic lines to the implement attachment can servethe double function of operating the locking mechanism and operating theworking implement. Thereby, the number of requisite hydraulic lines ofthe hydraulic line means is reduced, for instance, the number of linesmay be reduced from four to two. This decreases the extent of therunning of hydraulic lines along the crane arm as well as the number ofswivel passages, so that the assembly becomes simpler and thereby moreinexpensive.

Together with the measuring device, this entails a total solution thatcombines great handling safety and minimal line routing.

According to an additional preferred embodiment, the implementattachment comprises a first part arranged for permanent mounting toworking machines and a second part arranged for detachable connection tothe first part, the first part comprising a first lock plunger meansprovided with a first hydraulic actuator and arranged for lockingco-operation with the second part, and the second part comprising asecond lock plunger means provided with a second hydraulic actuator andarranged for locking co-operation with the implement, and the hydraulicmedium supply means being arranged for supply of hydraulic medium to thefirst as well as the second actuator and the measuring device beingarranged to measure the supplied volume of hydraulic medium for each oneof the actuators.

Many implements that the working machine is intended to handle requirethe possibility of great mobility, they should, among other things, berotatable and tiltable. Therefore, such functions are generallybuilt-into the implement attachment in a so-called tiltrotator. Incertain work operations or for certain implements, these requirementsare not imposed. Instead, the maximum available power is of interest.For this reason, it is advantageous to assign the rotational and tiltfunctions to a separate adapter unit between the arm of the workingmachine and the implement so that there is an option to connect animplement with or without this unit. Accordingly, in this case, theimplement attachment consists of two parts where the first part ispermanently attached to the arm of the working machine and the secondpart is the tiltrotator.

It is then important to easily be able to establish the correct couplingin the interconnection of the arm of the working machine and thetiltrotator as well as of the tiltrotator and the implement. This isguaranteed by this embodiment where the measuring device checks bothconnections. The simplicity that the check function according to theinvention affords is particularly valuable in this connection since itis two interconnections that should be guaranteed and since thetiltrotator causes that the other interconnection does not mediate thesame direct feeling to the driver.

According to an additional preferred embodiment, the lock plunger meanscomprises at least two parallel lock plungers displaceable in unison inthe same direction, the actuator being arranged also to displacehydraulic coupling means parallel to and in the same direction as thelock plungers.

Two or more lock plungers entail great coupling safety, and aco-ordination in this way of locking movement and interconnectionmovement of the hydraulics gives a quick and safe connection. Themeasuring device according to the invention is particularly expedient toapply in such a design. However, it should be appreciated that theinvention is applicable also to plungers arranged in other ways, e.g.,counter-directed and that are disposed in the cross-direction inrelation to the hydraulic interconnection direction.

The above-mentioned preferred embodiments are defined in the claimsdepending on claim 1. It should be emphasized that additional preferredembodiments naturally may consist of all feasible combinations of theabove-mentioned preferred embodiments.

The invention also concerns a working machine comprising an implementattachment in accordance with the invention, particularly in accordancewith anyone of the preferred embodiments of the same.

The invention concerns further a use of the invented implementattachment in order to attach an implement to the implement attachment,particularly in accordance with anyone of the preferred embodiments ofthe implement attachment.

The invented working machine and the invented use entail advantages ofthe corresponding kind as in the invented implement and the preferredembodiments of the same, and that have been accounted for above.

The invention is explained in more detail by the subsequent detaileddescription of embodiment examples of the same and with reference to theappended drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an implement attachment and workingimplement in a first relative position.

FIG. 2 is a perspective view of the components in FIG. 1 in a secondrelative position.

FIG. 3 is a perspective view of the components in FIG. 1 in a thirdrelative position.

FIG. 4 illustrates the correct coupling-together of an implement and animplement attachment.

FIG. 5 illustrates a first example of incorrect coupling-together.

FIG. 6 illustrates a second example of incorrect coupling-together.

FIG. 7 is a hydraulic diagram illustrating the measuring deviceaccording to the invention.

FIG. 8 illustrates a detail of the measuring device in FIG. 7.

FIG. 9 is a hydraulic diagram illustrating a second embodiment exampleof the invention.

FIG. 10 is a detail of the hydraulic diagram in FIG. 9 illustratinganother operational state.

FIG. 11 is an implement attachment according to a third embodimentexample of the invention.

FIG. 12 is a diagram illustrating a measuring device according to anadditional embodiment example.

FIG. 13 schematically shows a working machine provided with an implementattachment according to the invention.

DESCRIPTION OF EMBODIMENT EXAMPLES OF THE INVENTION

In FIGS. 1-3, a known system is described for the coupling-together ofan implement attachment and a working implement. What is shown in thesefigures and the description in connection with the same is accordinglycomprised in prior art, such as, for instance, is disclosed in EP 602165 mentioned and that is hereby referred to.

The system in FIG. 1 consists accordingly of an implement attachment 100and a working implement 200. The implement attachment 100 is intended tobe mounted on a working machine, which however is not shown in thefigure. The working implement 200 comprises an implement bracket 201that is a part that is coupled together with the implement attachment100 and is of a standardized design for different kinds of workingimplements. The active part of the working implement is not shown in thefigure. This is formed differently for different purposes. By thesystem, accordingly working implements intended for different kinds ofwork can be connected to the implement attachment 100 of the machine.

The implement attachment has a connecting part 101 that is formed with acapturing side 102 to the right in the figure and a locking side 103 tothe left in the figure. The capturing side 102 has two U-shaped profiledrecesses 104 only one of which is visible in the figure. The lockingside 103 has an L-shaped profile, and from this two lock plungers 105are arranged to be projectable in order to, together with the L-profile,form a U-shaped profile. In FIG. 1, the lock plungers are shown in theprojected position.

As is seen in FIG. 1, the lock plungers are provided with a bottomportion 106 that, together with the L-shaped profile on the locking side103 of the connecting part 101, will abut against the bracket pin 203during locking. Accordingly, the bottom portion 106 is an abutmentsurface for abutment against the bracket pin.

The implement bracket 201 of the working implement 200 is provided witha first bracket pin 202 arranged to co-operate with the capturing side102 of the implement attachment and a second bracket pin 203 arranged toco-operate with the locking side 103 of the implement attachment. Eachbracket pin may alternatively be replaced by a short pin stump at eachside end portion of the implement bracket.

When the implement attachment is to be coupled together with the workingimplement, the implement attachment is manoeuvred to a capturingposition illustrated in FIG. 2. This means that the U-profiles 104 ofthe implement attachment have been brought to straddle the first bracketpin 202 of the working implement. In this position, said bracket pin 202is accordingly in abutment against the bottom of the U-profiles oralmost in such a position. The implement attachment 100 is, in the sameposition, angled up, as is seen in the figure. The angle position is notparticularly critical at this stage and the angle between the implementattachment and the working implement can accordingly be any one within acertain interval.

Next step is, from the position shown in FIG. 2, to turn the implementattachment 100 and the working implement 200 in relation to each otherin a direction so that the implement attachment 100 is turned inwardtoward the working implement. This is done with the lock plungers in theinserted position so that the implement attachment can be turned in sofar that the second bracket pin 203 comes into position in theL-profile. Once in place, the components are ready for clamping. This iscarried out by the lock plungers 105 being brought to project so thatthe second bracket pin 203 is locked between the L-profile 103, and thelock plungers 15 are operated hydraulically between the two positionsthereof.

In FIG. 3, the components are illustrated in the clamped position. Theimplement attachment is provided with a number of hydraulic couplingunits and electric coupling units to be coupled together with thecorresponding units arranged on the working implement. The couplingunits are arranged on a coupling ramp of the respective unit. Thecoupling ramp of the implement attachment is mounted in such a way thatit is operated by the same hydraulic cylinders that operate the lockplungers. In FIG. 3, the back side of the coupling ramp 204 of theworking implement is visible while the front side thereof is obscured asis the coupling ramp of the implement attachment. Accordingly,projection of the lock plungers is carried out simultaneously with thecoupling-together of the coupling units. The invention is naturally notlimited to the design where this is carried out simultaneously.

Neither is the invention limited to a design where the lock plungers aremanoeuvred in the longitudinal direction of the implement attachment asin FIGS. 1-3. The lock plungers may accordingly be arranged so that theyare displaced perpendicular to this direction, i.e., parallel to thefirst bracket pin 202. In such a case, the lock plungers may stick intoopenings in the side pieces of the implement bracket. Also otherarrangements of the operation of the lock plungers are naturallyfeasible within the scope of the invention.

Likewise, the capturing means may be formed differently than asprong-like elements, i.e., the U-profiles, of the implement attachment,and the grip means may be formed differently than as a bar element,i.e., the bracket pin, of the working implement. Accordingly, theworking implement may, for instance, be provided with prong-like hooksfor the co-operation with complementary means of the implementattachment.

A critical stage in the coupling-together is when the implementattachment 100 is to be turned in from the position shown in FIG. 2 tothe coupled-together position shown in FIG. 4. In a correct positioning,the lock plungers 105 in the coupled-together position should bepositioned so that they, when they are projected, end up beneath thesecond bracket pin 203, i.e., inside the same.

In incorrect positioning, the lock plungers 105 end up so that theirouter ends strike against the second bracket pin 203 or so that they endup on the upperside of it, i.e., outside. Thereby, the implement 200will be able to come loose from the implement attachment 100 when theimplement is lifted, which means a risk of an accident.

In the following, it is described how the invention detects such a wrongpositioning so that action can be taken to correct the same. Theprinciple is to detect the length of the stroke movement of the plungerswhen the clamping movement is carried out. The stroke length will namelybecome different for the positionings mentioned above.

When the positioning is correct, as is illustrated in FIG. 4, the strokemovement will bring the lock plungers 105 past the bracket pin 203 tothe position where each lock plunger's 105 abutment surface 106 abutsagainst the bracket pin, which stops the continued movement of the lockplungers and thereby defines reference of the stroke length in thecorrect solution.

If the positioning is such that the outer ends of the lock plungers 105abut against the bracket pin 203, as is illustrated in FIG. 5, theirmovement is stopped at an early stage, i.e., the stroke length becomesmuch shorter than the reference length, indicating this type of wrongpositioning. It is true that in most cases it is fairly simple for thedriver to notice such an incorrect abutment with the eyes, and theinvention is therefore normally not so important for this indication.

If on the other hand the lock plungers 105 end up on the outside of thebracket pin 203, as is illustrated in FIG. 6, such a wrong positioningmay be difficult to detect. In such a positioning, the movement of thelock plungers 105 will not be stopped by the abutment surfaces 106 ofthe lock plungers striking against the bracket pin 203 without thestroke movement continuing as far as the stroke length of the hydrauliccylinder that constitutes the actuator allows. In this case, the strokelength becomes longer than the reference length and is thereby anindication of this type of wrong positioning.

The stroke length of the plungers is directly proportional to the volumeof hydraulic fluid that is supplied to the hydraulic cylinder of theactuator.

FIG. 7 shows the actuator for the lock plungers 105 in FIG. 1. Itconsists of two hydraulic cylinders 1, each plunger rod 2 of which isconnected with a respective lock plunger 105. The hydraulic mediumsupply means comprises a tank 3, a pump 4, a supply line 5, and a returnline 6. A reversing valve 7 connects the pump 4 with either the supplyline 5 or the return line 6. In the shown position of the reversingvalve 7, the pump is connected with the supply line 5. From the supplyline, the hydraulic fluid, usually oil, is distributed to a respectivebranch line 51 via a respective non-return valve 52 to each of thepressure sides of the hydraulic cylinders 1. Via a respective branchline 61, the return line 6 is connected with each of the return sides ofthe hydraulic cylinders 1.

In the supply line 5, the measuring device is arranged. It consists of arestriction 8 and a first 9 and a second 10 pressure sensor. When thepump 4 pumps oil to the respective pressure side of the hydrauliccylinders 1 through the supply line, the restriction 8 will cause apressure drop that is recorded by the pressure sensors 9, 10. Thisallows the determination of the volume that is supplied to the hydrauliccylinders 1 in a way that is explained in more detail in connection withFIG. 8.

The restriction 8 is a so-called sharp-edged restriction so that theflow through the restriction becomes independent of the viscosity of theoil, so-called hydraulic restriction. The restriction passage consistsof a wall 88 in which a through hole 89 is recessed. On the upstreamside, the hole 89 is mouthing in a plane wall so that the area changebecomes immediate at the edge of the hole 89 to the wall. On thedownstream side, the hole may mouth in a smoother area change. Usingthis type of restriction, the flow will only depend on the pressure dropacross the restriction, the density of the oil, and a constant C_(d). Bythe arrow, the direction of flow is indicated.

The flow through the restriction, which is derived from Bernoulli'sequation, is calculated according to the below expression and is validto a high accuracy under the conditions defined below

$Q = {A \times C_{d} \times \sqrt{\frac{2 \times \left( {P_{1} - P_{2}} \right)}{\rho}}}$

wherein

-   -   Q=the flow in I/s    -   C_(d)=the flow factor, i.e., C_(v)×C_(c)    -   A=the cross-sectional area    -   ρ=the density of the oil    -   P₁, P₂=the pressures before and after the restriction in MPa

The expression is valid under the condition that the flow velocitybefore and after the restriction is negligible in comparison with thevelocity in the restriction orifice, i.e., that Ø_(d)<<Ø_(D) and thatthe length L of the restriction in the direction of flow is negligiblein comparison with other dimensions. For an oil of mineral oil typewithin the viscosity range of 15-40 cst, the flow factor can be set toC_(d)=0.65-0.70.

By the measuring of P₁ and P₂ via the two pressure sensors 9, 10, adirect value of the instantaneous flow velocity Q through the supplyline 5 is obtained. A time integration, i.e., ΣQdt during strokemovement gives directly the supplied volume of oil as a result andthereby a measure of the stroke length.

In the table below, for a number of models of different sizes ofimplement attachments of the invention, interesting data are given. Inall models, the locking is carried out by two lock plungers and theactuator has two cylinders.

By volume locking, reference is made to the volume of hydraulic fluidthat is supplied when the correct lock position has been assumed by theplungers. Volume empty stroke is the volume that is represented by thefull displacement of the cylinders and that is attained when the lockposition is incorrect so that the lock plungers end up outside thebracket pin, wherein the plunger movement does not meet any obstacle.

Volume Stroke Over Diff. Stroke empty Volume length stroke empty ModelØ_(cyl) length stroke locking locking length locking Q [mm] [mm] [cm³][cm³] [mm] [mm] [%] A 20 59 37.1 33.9 54 5 8.5 B 32 59 94.9 79.6 49.59.5 16.1 C 35 60 115.5 103.7 53.9 6.1 10.2 D 40 65 163.4 149.5 59.5 5.58.5 E 50 70 274.9 249.4 63.5 6.5 9.3 F 55 75 356.4 297.0 62.5 12.5 16.7G 55 75 356.4 332.6 70 5 6.7 H 60 100 565.5 497.6 88 12 12.0 I 80 1291296.8 1241.6 123.5 5.5 4.3

As is seen in the rightmost column, the difference in volume and instroke length is significant between a lock position and an emptyposition, i.e., incorrect positioning. It varies between 4.3 and 16.7%depending on model size. This difference is, by the measuring methodindicated, by a wide margin sufficient to get reliable information if acorrect or an incorrect state is present, since the margin of error is afew percent.

FIGS. 9 and 10 illustrate a second embodiment example of the invention,wherein reversing valves are arranged to direct the hydraulic oil toeither the lock cylinders or the hydraulic couplings.

FIG. 9 illustrates the position when the hydraulics is coupled to lockthe working implement. In the valve plate 109, two change-over valves55, 56 are arranged. Each valve's entrance side is connected to arespective hydraulic line 5, 6 from the hydraulic power source 3. Eachvalve 55, 56 can be changed over into two different positions, for theconnection of the exit side to either the hydraulic coupling units 57,67 or to the hydraulic cylinders 16 a, 16 b; in the shown position, thehydraulic lines 24 a, 24 b are connected to the hydraulic cylinders 1.When the implement attachment 200 and the working implement have beenpositioned into the correct position as previously described, the supplyline 5 is pressurized so that, via the valve 55 and the hydrauliccylinder line 53, the plungers are displaced upward in the figure so asto thereby, on one hand, project the lock plungers 2 into lockingposition, and on the other hand bring the coupling units 57, 67 of thecoupling ramp 104 into connection with the coupling units 58, 68 of acoupling ramp 204 arranged on the implement bracket, as has beendescribed in connection with FIGS. 1-3.

When the locking step is accomplished, the valves 55, 56 are changedover to the position shown in FIG. 10. The lock plungers are now in thelock position and the coupling units 57, 67, 58, 68 of the couplingramps 104, 204 coupled together. Thereby, the lines 5, 6 are connectedto the hydraulics of the working implement via the valves 57, 67, 58,68. Thereby, the working implement is in the operative state. Betweeneach hydraulic coupling line 56, 66, it is arranged a junction fine 59,69 to the hydraulic cylinder line 53 that is pressurized during locking.In each junction line 59, 69, a non-return valve is arranged. These aredirected in such a way that flow is allowed from the respectivehydraulic coupling line to said hydraulic cylinder line but not in theopposite direction. Thereby, it is guaranteed that the pressure ismaintained on each hydraulic cylinder's pressure side during operationthanks to the fact that pressurized hydraulic oil from either one of thehydraulic coupling lines 56, 57 can be pressed into the hydrauliccylinder line 53 in the event that the pressure in the hydrauliccylinder tends to decrease. This by-pass-function thereby constitutes alocking block.

When the working implement is to be detached from the implementattachment, for instance for the exchange of implements, the valves arechanged over to the position shown in FIG. 5 and the lock plungers areretracted by the fact that each hydraulic cylinder's other side (theupper one in the figure) is pressurized by means of the reversing valve7 (see FIG. 7). Simultaneously, the coupling ramps 104, 204 aredisconnected from each other.

The measuring device 8, 9, 10 described in connection with FIG. 7 isarranged in the part of the supply line that is the hydraulic cylinderline 53.

FIG. 11 is a schematic illustration of an additional embodiment exampleaccording to the invention. In this case, the implement attachmentconsists of a first part 100 and a second part 300. The first part 100is permanently connected with the arm of the working machine 401 and isformed as the implement attachment 100 illustrated in FIG. 1.

The second part 300 is connected easily releasable from the first part100 and is, on the side that is intended for coupling with the firstpart 100, formed with a coupling bracket that corresponds to theimplement bracket of the implement 200 in FIG. 1. Coupling-together ofthe parts 100, 300 is carried out in a corresponding way as has beendescribed in connection with FIGS. 1-3.

The second part 300 has furthermore an implement coupling side for thecoupling-together with an implement 200. The coupling-together side isformed in the same way as for the implement attachment illustrated inFIG. 1, and coupling-together with the implement is carried out in acorresponding way.

The components of the first part 100 for the coupling-together with thesecond part 300 are in principle identical to the components of thesecond part 300 for the coupling-together with the implement 200. Animplement 200 can accordingly be applied to the working machine eitherdirectly on the first part 100 or via the second part 300.

The second part 300 is a so-called tiltrotor that has functionality forrotating and tilting the implement 200. It is coupled on when thesefunctions are required for the implement. It can be removed when thesefunctions are not required if, e.g., all available power is desired tobe utilized for the implement.

The supply line 5 is connectable to the hydraulic cylinders 1 of thefirst part 100 for the operation of the lock plungers thereof as well asto the hydraulic cylinders 1 a of the second part 300 for the operationof the lock plungers thereof. The measuring device 8, 9, 10 is utilizedfor checking both the connection of the tiltrotor 300 to the first part100 and the connection of the implement 200 to the tiltrotor 300. Asuitable valve system (not shown) assigns the measuring device 8, 9, 10to check the respective lock plungers and ensures that the pressure ismaintained in the cylinders 1 of the first part when the check functionis connected to the cylinders of the tiltrotor 300.

FIG. 12 is a diagram that illustrates an embodiment example where themeasuring device comprises additional components to process and forwardthe information from the pressure sensors 8, 9.

Each pressure sensor 8, 9 is, via a respective signal line 81, 91,connected to a calculation unit 80 that is programmed to calculate theinstantaneous flow through the supply line based on values of thedetected pressures. It is furthermore provided with a time integrationfunction for the calculation of the total supplied oil volume to thehydraulic cylinders of the actuator. In the calculation unit, there isalso stored data, including reference data of the volume upon correctconnection, and other information that is required to determine if thecorrect connection has been effected or not.

The information processed by the calculation unit 80 is fed via a signalline 82 to an indicator 83, which suitably is arranged in the workingmachine's driver cab. The indicator 83 may contain a display 84 thatpresents relevant data, and warning units such as, e.g., a warning light85 and/or a beeper 86.

In connection with the indicator 83, it is also possible to arrangeinput for commands from the driver, e.g., control signals to thecalculation unit to affect its parameters and algorithms and for theselection of modes of the presentation of the signals to the indicator83.

FIG. 13 illustrates a working machine 400 provided with an implementattachment according to the invention.

1. An implement attachment for a working machine, the implementattachment comprising: lock plunger means provided with a hydraulicactuator, said lock plunger means comprising at least one lock plunger,said lock plunger means being arranged for locking co-operation with animplement; and hydraulic medium supply means for the supply of hydraulicmedium to said hydraulic actuator, said hydraulic medium supply meansbeing provided with a measuring device arranged to measure the volume ofhydraulic medium that is supplied to said actuator.
 2. The implementattachment according to claim 1, wherein said hydraulic medium supplymeans comprises a supply line, and said measuring device is arranged tomeasure the flow through the supply line.
 3. The implement attachmentaccording to claim 2, wherein said measuring device comprises arestriction in said supply line and a pressure sensor on each side ofsaid restriction.
 4. The implement attachment according to claim 3,wherein said measuring device comprises a calculation unit arranged toreceive signals from each said pressure sensor, said measuring devicebeing provided with a calculation program comprising an algorithmdefining the flow velocity through said supply line versus pressurelevels detected by the pressure sensors and further comprising anintegration algorithm integrating the flow velocity for the calculationof the supplied quantity of hydraulic medium.
 5. The implementattachment according to claim 4, wherein said measuring device issignally connected with an indicator.
 6. The implement attachmentaccording to claim 5, wherein said indicator is arranged to trigger awarning signal when exceeding a predetermined measured volume.
 7. Theimplement attachment according to claim 1, wherein said at least onelock plunger is provided with an abutment surface arranged for abutmentagainst a body of the implement when the implement is clamped to theimplement attachment.
 8. The implement attachment according to claim 2,wherein the implement attachment comprises hydraulic coupling means forconnection to the implement and valve means for selective connection ofsaid supply line to either said actuator of said lock plunger means orto said hydraulic coupling means.
 9. The implement attachment accordingto claim 1, and further comprising: a first part arranged for permanentmounting to the working machine; a second part arranged for detachableconnection to said first part; said first part comprising a first saidlock plunger means provided with a first said hydraulic actuator andarranged for locking co-operation with said second part; said secondpart comprising a second said lock plunger means provided with a secondsaid hydraulic actuator and arranged for locking co-operation with theimplement; said hydraulic medium supply means being arranged for supplyof hydraulic medium to said first and said second hydraulic actuator;and said measuring device being arranged to measure the supplied volumeof hydraulic medium for each one of said first and second hydraulicactuators.
 10. The implement attachment according to claim 1, whereinsaid lock plunger means comprises at least two parallel lock plungersdisplaceable in unison in the same direction, each said hydraulicactuator is arranged to displace a hydraulic coupling means parallel toand in the same direction as said lock plungers.
 11. The implementattachment according to claim 8, wherein said lock plunger meanscomprises at least two parallel lock plungers displaceable in unison inthe same direction, each said hydraulic actuator is arranged to displacesaid hydraulic coupling means parallel to and in the same direction assaid lock plungers.
 12. A working machine comprising an implementattachment according to claim
 1. 13. The use of an implement attachmentaccording to claim 1 in order to attach an implement to the implementattachment.